Cataract surgery clinicians in Ankeny, Iowa
CMS lists 8 clinicians with a primary specialty of Ophthalmology who have billed Medicare for at least one cataract surgery and practice in Ankeny, Iowa (details below).
Cataract surgery volume
| Clinician | Cataract surgeries billed | Percentile rank |
|---|---|---|
| Matthew Rauen, MD | 1,958 | 99% |
| Thomas Meirick, MD | 1,700 | 99% |
| Gregory Christiansen, MD | 898 | 98% |
| Mark Meyer, MD | 267 | 76% |
| Samuel Whittier, MD | 256 | 74% |
| Audrey Ko, MD | 36 | 33% |
| David Massop, MD | 16 | 24% |
| Riley Bylund, MD | 1-10 | 21% or below |
Sorted by the number of cataract surgeries billed to Medicare, highest first, not by quality or skill. CMS suppresses counts between 1 and 10 to protect patient privacy and publishes the range instead.
Understanding CMS Data
CMS's "Cataract surgery" category combines specific billing codes for cataract surgery to calculate the number of times each clinician billed Medicare for a "Cataract surgery." These include lens replacement surgery and YAG laser capsulotomy, a laser treatment that can follow cataract surgery. CMS reports only procedures that clinicians billed to Original Medicare and Medicare Advantage. Therefore, CMS's procedure volume data does not include procedures that clinicians may have performed on patients who have other health care coverage (e.g., commercial insurance, self-pay, or the VA). Billing variation and coding errors can also affect CMS's data. Therefore, the number of procedures that CMS reports for a clinician may be higher or lower than the actual number of cataract surgeries a clinician performed during the reporting period. Lastly, only clinicians with a primary specialty of Ophthalmology (as reported to Medicare) are presented.
Source: Centers for Medicare & Medicaid Services (August 18, 2026 release).